Traditional detergents often contain numerous chemicals in order to improve cleaning activity. For example, detersive cleaning agents often contain builders, sequestrants, chelating agents, surfactants, alkalinity sources and a variety of additional chemicals in order to tailor a detergent for a particular cleaning activity. However, many consumers prefer to use household cleaning agents with minimal chemicals and non-hazardous materials. Exemplary natural or homemade “detergent-free” cleaners often include baking soda and baking powder. The use of fewer chemicals is favored by many consumers due to a variety of benefits, such as minimizing health risks, lower costs and “going green”.
Among the various chemical additives often required for detergents are components to counteract the effects of water hardness. Hard water is known to reduce the efficacy of detergents. One method for counteracting this includes adding chelating agents or sequestrants into detersive compositions that are intended to be mixed with hard water in an amount sufficient to handle the hardness. However, in many instances the water hardness exceeds the chelating capacity of the composition. As a result, free calcium ions may be available to attack active components of the composition, to cause corrosion or precipitation, or to cause other deleterious effects, such as poor cleaning effectiveness or lime scale build up. Further, some chelators and sequestrants (e.g., phosphates and NTA) have been found to cause environmental and health issues.
Another method for addressing water hardness issues currently used is to soften water via ion exchange, e.g., by exchanging the calcium and magnesium ions in the water with sodium associated with a resin bed in a water softening unit. The calcium and magnesium adhere to a resin in the softener. When the resin becomes saturated it is necessary to regenerate it using large amounts of sodium chloride dissolved in water. The sodium displaces the calcium and magnesium, which is flushed out in a briny solution along with the chloride from the added sodium chloride. When water softeners regenerate they produce a waste stream that contains significant amounts of chloride, creating a burden on the system, e.g., sewer system, in which they are disposed of, including a multitude of downstream water re-use applications like potable water usages and agriculture. Further, traditional water softeners add to the salt content in discharge surface waters, which has become an environmental issue in certain locations.
Other components which improve the cleaning function of detergents include alkalinity sources. Alkaline cleaning compositions are known to be effective in various applications. For example, alkaline cleaners are effective as grill and oven cleaners, ware wash detergents, laundry detergents, laundry presoaks, drain cleaners, hard surface cleaners, surgical instrument cleaners, transportation vehicle cleaning, dish wash presoaks, dish wash detergents, beverage machine cleaners, concrete cleaners, building exterior cleaners, metal cleaners, floor finish strippers, degreasers and burned-on soil removers. For some applications, cleaning agents having a very high alkalinity are most desirable. For example, floor stripping compositions for removal of floor finishes are highly alkaline.
In many applications, these highly alkaline cleaning compositions must be transported, handled and applied by workers. However, such agents can be dangerous and can cause burns to exposed skin, particularly in the concentrated form. As the alkalinity of the compositions increases, the possible risk to workers also increases. Great care must therefore be taken to protect workers who handle concentrated highly alkaline materials. Accordingly, an embodiment of the invention is to provide in situ cleaning systems requiring no more than household cleaning agents having a full range of detersive cleaning effects.
An additional embodiment of the invention is to provide an in situ cleaning system and methods for producing cleaning use solutions that are efficient and sustainable.
A further embodiment of the invention is to provide in situ cleaning systems for onsite generation of cleaning agents without requiring expensive or dangerous transportation.
These and other embodiments of the invention are set forth herein the description of the invention.